Transactions and blocks as typed byte structures
The rust-bitcoin crate gives you direct, typed access to the exact byte-level structures that make up the Bitcoin protocol: Transaction, TxIn, TxOut, Block, BlockHeader, Script, and more. This is different from working through a wallet abstraction or an RPC call that hands you JSON. When you build a Transaction struct by hand, you're setting the same fields, version, lock_time, the input vector, the output vector, that get serialized into the exact bytes a Bitcoin node will hash, sign, and broadcast. Understanding this layer matters because every higher-level tool, BDK included, is ultimately just a more convenient way of producing these same structures.
Parsing works the same way in reverse. Given raw transaction bytes from the network or a block explorer, rust-bitcoin's Decodable trait deserializes them into these typed structs, so you can programmatically inspect inputs, outputs, witness data, and script types without writing your own binary parser. This is the foundation for anything that needs to reason about Bitcoin data directly: block explorers, fee estimators, chain analysis tools, and custom wallet software all sit on top of this layer.